Improvement in wood-screws



H.. ALYDOTY.`

, WQOD-SCREW. No. 173,115.

Zlz/esses. Lm/2M aM/w Patente@ Feb. 8, 18726.

jzyenl'ar UNITED STATES PATENT QEEIcE.

HENRY A'. DOTY, 0E JANEsvrLLE, wlscoNsiN.

IMPROVEMENT IN `WOQD-SCREWS.

Speciiicationforming partl of Letters Patent No. 173,1l5, dated February 8, 1876; application filed June 6, 1873.

To all whom it may concern:

Be it known that I, HENRY A. DOTY, of Janesville, Rock county, State of Wisconsin, have invented Improvements in WoodScrews, of which the following is a specification:

The object of this invention is a Wood-screw constructed, as fully described hereafter, to render any preliminary piercing of the wood unnecessary,amdv to insure the travel of the screw in-the direction in which it is started; and this object 1 effect by constructing the screw with a projection egtendpg beyond the thread, as shofwnrrin the accompanying drawing, the threiiguresfofwhich .il1ustrate the screw and theifdilelltnyays,.innvhich it may -b dwilltlihenmdmaking a hole to receive them, and afterthey are fairly entered, the screw, in consequence of the sh'ape of the gimlet-point, will follow the grain of the Wood, and turn aside from a straight course on coming in contact with cross-grain or knots. v

Myinvention provides a remedy for the abo-ve defect, as the center point, being sharp, pierces the wood easily, no matter what is the resistance of cross-grain or knots, and necessarily advances 4without a deviation from a` straight line, thereby preventing the breaking of the screw, which would be'the case if the screw had to turn aside for every obstruction it niet. Again, the sharp point answers the purpose of an aWl to exactly locate the starting place of the screw on any surface.

I claim- A wood-screw provided with a vpointed projection, D, extending beyond the thread, as set forth. y

In testimony that I claim the foregong'I have hereunto set my hand this 28th day of May, 1873.

HENRY A. DOTY.

Witnesses:

A WM. G. HELLER,

, H. P. EHRLINGER. 

